I feed him science diet chicken and rice dry food. He is an indoor cat. He vomits in chunks. It won't happen for a while then it will happen three times in a night. I haven't noticed any litter box changes but I have two cats so it's hard to hell. There is a bit of diareha but that could be either one. He seems to be drinking the same amount. I have taken him to a vet once for a cyst on his face about a year ago. The vet is a general practise.